Improvement by heating of the electronic conductivity of cobalt spinel phases, electrochemically synthesized in various electrolytes
DOUIN, Myriam
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
Direction de la recherche
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Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
Direction de la recherche
DOUIN, Myriam
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
Direction de la recherche
< Réduire
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
Direction de la recherche
Langue
en
Article de revue
Ce document a été publié dans
Journal of Solid State Chemistry. 2009, vol. 182, n° 5, p. 1273-1280
Elsevier
Résumé en anglais
The nature of the alkaline electrolyte (based on KOH, NaOH, LiOH), in which Co<sub>3</sub>O<sub>4</sub> spinel type phases are synthesized by electrooxidation of CoO, is shown to play a key role on the composition, the ...Lire la suite >
The nature of the alkaline electrolyte (based on KOH, NaOH, LiOH), in which Co<sub>3</sub>O<sub>4</sub> spinel type phases are synthesized by electrooxidation of CoO, is shown to play a key role on the composition, the structure and the electronic conductivity of the materials. In the materials, prepared in pure LiOH electrolyte or in mixed ternary electrolyte (KOH, NaOH, LiOH), Co<sup>4+</sup> ions are present in the octahedral framework, which entails electronic delocalization in the cobalt <i>T</i><sub>2</sub><i><sub>g</sub></i> band and a high conductivity. The structure of the sample, synthesized in KOH, is on the opposite closer to that of ideal Co<sub>3</sub>O<sub>4</sub>, with only Co<sup>3+</sup> in the octahedral sublattice, which leads to a semi-conducting behavior. Whatever the initial material, a thermal treatment induces an increase of the Co<sup>4+</sup>/Co<sup>3+</sup> ratio in the octahedral network, resulting in a significant increase of the electronic conductivity.< Réduire
Mots clés en anglais
Spinel
Cobalt oxide
Electronic conductivity
Alkaline battery
Origine
Importé de halUnités de recherche